1. Field of the Invention
The present invention generally relates to integrated circuits and more particularly to an improved integrated circuit that includes passive devices formed over active devices using a conductive polymer.
2. Description of the Related Art
Integrated circuits for wireless applications are driven to higher levels of integration to reduce the processing and design costs. To integrate passive components such as RF (radio frequency) circuits with the digital core is highly desirable. Today's mobile cellular phone has hundreds components. Most of them are passive devices. To integrate them into a single chip is not only cost effective, but also can reduce the power consumption in the system. However, the passive components, such as inductors, capacitors and resistors, and those that are used for the RF and analog functions, consume large chip area due to the size of these elements. In addition, these elements tend to interact strongly with the active transistor RF devices from substrate coupling.
Therefore, there is a need to include such passive devices within the digital core without consuming valuable chip area and while avoiding undesirable interaction between RF components and the sensitive components within the digital core. The invention discussed below addresses these issues by presenting a novel structure and method to form the same. The conventional design uses metal conductors to fabricate such passive components. These are limited by thickness of the chip technology and occupy valuable chip area. Then placing passive components on top of the chip save chip area, make them larger in size and places far away from the device components on the chip thereby reducing interference and allowing better isolation.